package com.xiaolun.netty.websocket;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.stream.ChunkedWriteHandler;

public class MyServer {
	public static void main(String[] args) throws Exception {
		//创建两个线程组
		EventLoopGroup bossGroup = new NioEventLoopGroup(1);
		EventLoopGroup workerGroup = new NioEventLoopGroup(); //8个NioEventLoop
		try {
			ServerBootstrap serverBootstrap = new ServerBootstrap();
			serverBootstrap.group(bossGroup, workerGroup);
			serverBootstrap.channel(NioServerSocketChannel.class);
			serverBootstrap.handler(new LoggingHandler(LogLevel.INFO));
			serverBootstrap.childHandler(new ChannelInitializer<SocketChannel>() {
				@Override
				protected void initChannel(SocketChannel ch) throws Exception {
					ChannelPipeline pipeline = ch.pipeline();
					//因为基于http协议，使用http的编码和解码器
					pipeline.addLast(new HttpServerCodec());
					//是以块方式写，添加ChunkedWriteHandler处理器
					pipeline.addLast(new ChunkedWriteHandler());
					/**
					 说明
					 *1. http数据在传输过程中是分段, HttpObjectAggregator ，就是可以将多个段聚合
					 *2. 这就就是为什么，当浏览器发送大量数据时，就会发出多次http请求
					 */
					pipeline.addLast(new HttpObjectAggregator(8192));
					/**
					 说明
					 1. 对应websocket ，它的数据是以 帧(frame) 形式传递
					 2. 可以看到WebSocketFrame 下面有六个子类
					 3. 浏览器请求时 ws://localhost:7000/hello 表示请求的uri
					 4. WebSocketServerProtocolHandler 核心功能是将 http协议升级为 ws协议 , 保持长连接
					 5. 是通过一个 状态码 101（/hello2要和hello.html对应）
					 */
					pipeline.addLast(new WebSocketServerProtocolHandler("/hello2"));

					//自定义的handler ，处理业务逻辑
					pipeline.addLast(new MyTextWebSocketFrameHandler());
				}
			});
			//启动服务器
			ChannelFuture channelFuture = serverBootstrap.bind(7000).sync();
			channelFuture.channel().closeFuture().sync();
		} finally {
			bossGroup.shutdownGracefully();
			workerGroup.shutdownGracefully();
		}
	}
}
